U4R1:Race — a socially defined population that is derived from distinguishable physical characteristics.种族——根据明显的外貌特征划分的社会特定人群。U4R3 PA:In many Western societies, such as the United States or Canada, which are made up of many different nationalities, ......许多西方国家如美国或加拿大，都有着不同的民族、......Some people use the "race", which ____________________ (来源于不同的身体特征), to indicate that different races____________________(由不同的国家组成).